Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already declare readOnlyHint=true and openWorldHint=false, so safety is covered. The description adds meaningful context by enumerating the dimensions of the comparison (trust scores, compliance, providers, MCP, pricing), which effectively signals what the response contains even though no output schema exists; it does not cover error behavior for unknown slugs.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

A single front-loaded sentence with no filler; the comparison target and the dimensions are stated immediately, and nothing is repeated.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a simple read-only comparison tool with one parameter and no output schema, the description is nearly sufficient: it conveys scope and the compared attributes. The main gap is the slug provenance/format and behavior on invalid input.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema coverage is 0% and the single parameter is an array of strings, so the description must carry the meaning. It does clarify that the array holds two to five AI tools, but that duplicates minItems/maxItems already in the schema, and it never explains the expected slug format or where slugs come from (e.g., search_tools).

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description pairs a specific verb ('Compare') with a specific resource ('AI tools') and bounds the scope to two to five items, plus it names the compared dimensions (trust scores, compliance, model providers, MCP, pricing). It does not explicitly contrast itself with search_tools or get_tool, so the distinction from siblings is only inferable from the comparison-vs-lookup framing.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

Usage is implied by the 'compare ... side by side' phrasing and the 2-5 constraint, which suggests when a multi-tool comparison is appropriate. There is no explicit statement about when not to use it or which sibling handles single-tool lookup or discovery, so the agent must infer routing.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.